Supporting head for abrasive disks



June 25, 1946.

w. STEVER SUPPORTING HEAD FOR ABRASIVE DISKS Fil ed Sept. 15, 1945 5 Sheets-Sheet 1 R r w N6. t S N m a u L L W PICIB A TTORNE Y 3 Sheds-Sheet 2 INVENTOR William Sc-ev e1.

ATTORNEY June 25, 1946. w. STEVER SUPPORTING HEAD FOR ABRASIVE DISKS Filed Sept. 15, 1943 June 25, 1946. w. STEVER SUPPORTING HEAD FOR ABRASIVE D ISKS Filed sein. 15, 1945 3 Sheets-Sheet 3 EHW R Y. Y m m 3 w my 0 w w g 1 m A t sfi a m 7 l a I W Q1 Psmml June 25, 1946 UNITED STATES PATENT OFFICE scrroarnzo 1mm roa annasrvn msxs William Stever, Philadelphia, Pa., assignor to Edward G. Budd Manufacturing Company, Phila- I delphia, Pa., a corporation of Pennsylvania Application September 15, 1943, Serial No. 502,422

2 Claims. 1

The invention relates to supporting heads for polishing disks such as there are used for grinding of! or polishing the surfaces of sheet metal stampings prior to painting.

Among the objects of the invention is a head which permits the easy attachment or removal of the abrasive disk, an object of greatest importance because such disks wear out rather rapidly and a great number of them are used by one workman in the course of one working day.

Another object of the invention is a head for an abrasive disk which has no sharp projecting parts liable to cause injury to the workman or mar the workpiece to be polished.

A still further object of the invention is a supporting head of the'indicated type which holds the abrasive disc so firmly that there is no danger of the disk getting loose and causing injury by being whirled around in the shop.

An object of the invention is also means for the attachment of a plate or pad supporting the abrasive disk in such a manner that this plate can likewise easily be exchanged and is nevertheless held securely in place.

The above and other objects of the invention are achieved by the formations of the head and of the portions of the disk and the backing plate which are shown in the attached drawings and described in the following. a

In the drawings: I

Fig. 1 is a fragmentary plan view of an abrasive disk and its supporting head, certain portions being broken away for the purpose of showing the interior construction.

Fig. 2 is a section along line 2--2 of Fig. 1.

Fig. 3 is a fragmentary rear view of an abrasive disk and of the member for holding it.

Fi 4 is a section along line 1-4 of-Fig. 3.

1 into the central member II and connected such as by a flexible shaft to a driving motor (not shown). Members i2 and I2 are secured in their relative positions by a set screw l5.

Member I! has a marginal plane portion i8 and a central recessed conical portion IT. The mem.,

ber. I2 projects beyond the central portion of member l4 and is provided with short cylindrical ribs I l which carry radially extending ribs l9 and 20. Pins 2| project inwardly from one end of each of the ribs I8, 20. There are three ribs l8 with wings I9, each of these structures extends over less than Vs of the circumference leaving a somewhat wider space between them.

The circular metal plate 22 is shaped corresponding to the shape of the surfaces It, I i, but extends outwardly beyond it. The outwardly extending portion is secured'by rivets 2! to a flexible disk 24 which may consist of fiber, metal, or any other suitable material. The disk 24 extends inwardly beyond the rivets 23 but is slightly spaced from the inner portion of the disk 22.

At its inner circumference the disc 22 is provided with radially inwardly projecting portions 25 which are adapted to enter between to be turned under the extensions it into the position illustrated in Figs. 1 and 2. The rotation of the portions 25 is limited by the aforesaid 'pins 2|.

The detachable central member 28 has radially outwardly projecting segments 21 near its one end which are adapted to enter between th exten- Fig. 5 is a view similar to Fig. 1 but of a modifled form of the invention. I

Fig. 6 is a section along line 8-10! Fig. 5.

Fig. '7 isv a plan view oi the supporting head shown in Figs. 5 and 6. V

Fig. 8 isan exploded perspective view of the supporting head, the backing pad and the abrasive disk with its holder of a third embodiment of the invention. 7 Fig. 9 is a fragmentary plan view partly in section of the construction shown in Fig. 8. I

Fig. 10 is a section mainly along line ifl-IO but partly along line lI'-ll' of Fig. 9.

The'supporting head illustrated in Figs. 1 and 2 consists mainly of three concentric members H, I: and II which are screw threaded into one another. The driving shaft I4 is screw threaded sions 20 and to engage the latter by turning movement. Here again the movement is limited by the pins 2| The outer portion of the member 2' has a radially flaming portion 28 with a flat outer surface 20 and a shallow conical surface II. The latter has two radial substantially square extensions II which fit into corresponding recesses of the abrasive disk 32. The abrasive disk may have radial slots 23 which adapted them for use with other known types of heads.

' For removing the abrasive disk 32, it is simply turned counter-clockwise. The disk takes the central holding member 28 along and brings it out of engagement with the extensions 200i the member l2. For inserting a new disk, the member 2| is put in place on the central portion of the disk, then pushed into the head and given a slight twist so that its projections 21 grip under the extensions 20 of the member l2. The rochange of the disk or plate 22 in case it should be worn out or the substitution of a disk of different flexibility as desired, is just as easy as and corresponds to the exchange of the abrasive disk 33. I

ventire head is light and compact, does not require great amounts oi. valuable metal and can, due to its light weight, easily be operated without causing undue fatigue of the workman;

In the embodiment shown in Figs. 5, 6 and 7, thereis again a driving shaft 34 and a head composed of three members 35, 86 and I1 screw threaded into one another. There is, furthermore, Just as in a preceding embodiment, a plate 40 attached to a backing plate or pad ll and releasably engaged with the member 36 by inward projections 38 which engage outward projections 39 closed at one end by a pin 40'. The holding member for the abrasive disc ll consists in this f4 7 amount of this offset is so small that it does not prevent the disengagement between the members if suflicient force is applied.

The invention is not restricted to the illustrated embodimentsbut is liable to such modifications as will occur to those skilled in the art. All such modifications are intended to be covered by the attached claims.

What is claimed is:

1. Head for holding abrasive disks comprising a fiat body of rotation adapted on one side for' posite side concentrically recessed; concentric embodiment of a nut 42 having an outwardly extending plate 43 which presses the inner portion of the disk 44 and the pad 4] against plate 40. This construction affords a firmer grip of the abrasive disk, but it requires slightly more time to exchange a disk because the member 42 has to be rotated several times as compared with the short movement required for the corresponding member 26 of the first embodiment.

The embodiment shown in Figs. 8, 9 and 10 is quite similar to the embodiment shown in Figs. 1 to 4, indeed, so similar that the same reference numerals are used for the corresponding parts and so that attention may be directed to the description of the first embodiment. The illustration of this last embodiment will also make the construction to the embodiment shown in Figs. 1 to 3 more easily understood. The outstanding difference consists in the details illustrated in Figs. 9 and 10. The extension of the member I2 and the projection 21 are both slightly oil'set at 45 so that the portion of the extension 20 remote from the pin 2! is slightly thickerand the portion or the projection 21 close to the pin 2| is slightly thicker than the respective remaining portion. The amount of this offset is exaggerated in Fig. 10. Its purpose is to hold the two members firmly together by letting the thickened portion of the projection il enter behind the v thinner portion of the extension 2|. Yet, the

rib formed projections integral with said body extending into therecess from the bottom thereof; radial outward and inward sector shaped integral extensions on said projections; a holding plate for a backing pad engaging the outward extensions with mating radially inwardly directed extensions on the margin of a central opening in the plate; a holding member for an abrasive disk engaging said inward extension with mating extensions formed on the outside of a cylindrical portion of said holding member; the arrangement being such that said holding plate and'said holding member upon rotation relative to said body may be disengaged from and reengaged with said body.

2. ,Head for holding abrasive diskscomprising I a cylindrical body of rotation adapted on one side for the connection with a driven shaft while its opposite side is provided with a recess and mtegrally with supporting means arranged concentrically to the axis of rotation and projecting into the recess from the bottom thereof; radially outwardly extending sector shaped extensions on and integral with said means and arranged in the WILLIAM BTEVER. 

